Add snippets for inserting figures and links to them in xhtml.

These probably don’t belong in the repo, and I should decide on a better way of
keeping snippets around.
Add nginx syntax.
Remove Command-T.

Don't like the dependency on Ruby.
Add autocommand for python indentation.
Remove Command-T from .gitmodules.
Add ctrlp as vimscript Command-T replacement.
Mappings for CtrlP.